Morphological and biochemical bases of resistance of eggplant (Solanum melongena L.) and okra (Abelmoschus esculentus [L.] Moench.) to the cotton leafhopper [Amrasca biguttula (Ishida)].
1994
Taylo L.D.
Greater preference for Smooth Green Over Accession 12 was demonstrated by the higher number of adults that settled per plant and greater number of newly hatched nymphs. Length and density of trichomes and leaf hardness were significantly greater in Accession 12; leaf thickness and number of branches did not differ significantly, while midrib width was significantly narrower in Smooth Green and apparently not influencing leafhopper oviposition. Both okra varieties possess simple (unbranched) and tufted (3 branches) trichomes on the lamina; simple and forked (2 branches), non-glandular on the midrib. Fewer eggs were deposited and fewer nymphs emerged on Accession 12 than on Smooth Green. They were significantly and negatively correlated with length and density of trichomes. Cotton leafhopper is a phloem feeder on both resistant and susceptible eggplant and okra. The amounts of plant sap ingested and assimilated and the honeydew excreted were greater on the susceptible than on the resistant variety. The honeydew spots on the filter paper treated with bromocresol green were less dispersed on Smooth Green; some coalesced forming bigger spots. On Accession 12 the honeydew deposits were in tiny spots, suggesting insect restlessness. The lesser food ingestion on the resistant host plants was attributed to leafhopper restlessness and harder leaf tissues. In both eggplant and okra, total free sugars and starch were the variable chemical components when susceptible and resistant varieties were compared.
Show more [+] Less [-]AGROVOC Keywords
Bibliographic information
This bibliographic record has been provided by Wolters Kluwer